* U.S. imposed new sanctions on Iran’s iron, steel
* Iran exported around 14 mln T iron ore in 2018 - Jefferies
* Market worried about waning demand at mills - trader (Updates closing prices)
BEIJING, May 9 (Reuters) - China’s iron ore futures were shaky on Thursday as investors struggled between waning demand at steel mills and another supply shock after U.S. imposed new sanctions on Iran.
The most-traded iron ore contract for September delivery on the Dalian Commodity Exchange closed 0.1 percent higher at 644.5 yuan ($94.60) a tonne after a slight price correction in the morning.
It jumped more than 4 percent to as high as 661.5 yuan a tonne on Tuesday in the wake of Vale’s announcement of holding off reopen at its Brucutu mine with annual capacity of 30 million tonnes.
Brazil’s Vale SA said on Wednesday its iron ore production and sales slumped in the first quarter from a year earlier, down 11 percent and 22 percent, respectively.
U.S. President Donald Trump on Wednesday imposed new sanctions on Iran, covering iron, steel, aluminium and copper sectors, the country’s largest non-petroleum-related sources of export revenue and 10 percent of its export economy.
Iran exported nearly 14 million tonnes of iron ore in 2018, accounting for 1 percent of total seaborne iron ore supply of the year, according a note from Jefferies.
“We had expected Iranian exports to increase to around 20 million tonnes this year as a result of the Vale supply issues. Now Iranian iron ore exports are likely to approach zero for as long as these sanctions last,” said Jefferies’ analysts.
However, investors of Dalian iron ore were fretting about actual demand of the steel-making raw material despite more supply shocks.
“Investors are generally scared of high iron ore prices now as demand at steel mills is expected to fall soon,” said a Shanghai-based iron ore trader.
Tangshan, top steel producing city in China, had stepped up its production restrictions in May as part of the anti-smog campaign.
“Market also worried about steel orders in the second half of this year, which would lead to falling profit margins at mills and therefore increasing pressure on raw materials,” said the trader.
Benchmark Shanghai rebar prices edged down 0.1 percent to 3,737 yuan a tonne, while hot-rolled coil dropped 0.8 percent to 3,669 yuan.
Dalian coking coal lost 0.9 percent to 1,357 yuan.
Coke prices extended gains for a fifth day and ended at 2,156 yuan. ($1 = 6.8132 Chinese yuan renminbi) (Reporting by Muyu Xu and Dominique Patton; editing by Gopakumar Warrier)